Interrupter-spark-suppression method and device



W. J. CRUMPTON.

INTERRUPTER SPARK SUPPRESSION METHOD AND DEVICE.

APPLICATION FILED APR.26, 1917.

1,350,300. Patented Aug. 24,1920.

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Wu.- $110 Guam OZ Evanston, in the county of Cook and State UNITED STATES PATENT OFFICE.

WILLIAM J. CRUMPTON, 0F EVANSTON, ILLINOIS.

Specification of Letters Patent.

Patented Aug. 24, 1920.

Application filed April 26, 1917. Serial No. 164,735.

T 0 all whom it may concern:

Be it known that I, WILLIAM J. CRUMP'roN, a citizen of the United States, residing at of Illinois, have invented certain new and useful Improvements in Interrupter-Spark- Suppression Methods and Devices, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to a new method and arrangement of apparatus for the suppression of sparking in an electrical interrupter and has for its object the provision of a method and arrangement of apparatus that is effective in completely suppressing the spark which tendsto jump across the contacts of the interrupter upon breaking thereof and which does not require special and continuous attention and adjustment nor renewal or replacement of the parts of the apparatus.

Before proceeding with the description of the device of my invention and to enable a more comprehensive understanding of the various novel features and improvements of the invention over the devices of this class which have been employed in the past,

it may be well to refer here in a general way to such prior arrangements. In these prior arrangements it has usually been the practice to utilize a condenser connected directly across the contacts of the interrupter and to maintain such connection at all times.

This arrangement results in damage to the contacts of the interrupter since the condenser discharges through the contacts each time the circuit is closed, or in other words, at every make, and if the condenser capacity is ample to absorb the spark at the break or upon opening of the circuit the condenser discharge on the closing of the circuit results in burning of the contacts. To avoid this objection it has sometimes been the practice to utilize a condenser havin a capacity insufficient to absorb the spar completely at the break but such arrangement requires continual attention and replacement of contacts, and for that reason does not operate satisfactorily.

To avoid the shortcomings of these prior devices and to produce an effective spark suppression means and method I contem plate placing a condenser in shunt with the gap or contacts of the interrupter at the time of the break, disconnecting the condenser shunt from the gap after the break has occurred and allowing the condenser to discharge during such disconnection of the shunt from the gap and before the condenser 18 again connected in shunt with the gap.

The method and arrangement of apparatus of my invention are applicable to any and all forms of electrical interrupters which operate to make and break an electric circuit and in which it is desirable to suppress any sparking between the contacts of the interrupter at such make and break.

My invention will be described in detail in connection with the accompanying drawin s, wherein- Figurel is a diagrammatic circuit drawing showing the method and apparatus of my inventlon applied to a rotary interrupter;

Fig. 2 is a diagrammatic circuit drawing showing a modified arrangement for connecting and disconnecting the condenser across and from the spark gap;

Fig. 3 is a diagrammatic circuit drawing showing another modification of my invention.

Fig. 4 is a diagrammatic circuit drawing showing the method and apparatus of my invention applied to an interrupter of the vibratory type; and

Fig. '5 is a diagrammatic circuit drawing showing a modified arrangement of the apparatus shown in Fig. 4.

Referring first to Fig. 1, 6 designates a rotary form of interrupter comprising the two disks 7 and 8, the disk 8 forming the slip ring of the interrupter and the disk 7 the interrupter proper. The slip ring 8 has electrical engagement with the brush 9 in turn connected by the wire 10 with one side of the battery 11. The other side of the battery is connected by the conductor 12 with one side of the load. The interrupter disk 7 contains the several insulated seg ments shown at 13 and 13 and the several conductor segments shown at 14 and 14 arranged to connect electrically with the two brushes shown at 15 and 16. The brush 15 is connected with the conductor shown at 17 which extends to one side of the load and which is connected to one side of the condenser shown at 18. The other side of the condenser is connected with the conductor 19 leading to the brush. 16. The brush 16 is angularly displaced with regard to the brush so that upon rotation of the 1nter-. rupter disks in the direction indicated by the arrow the brush 15 will engage and leave the conductor segments 14 of the in terrupter disk before the brush 16 engages and leaves such conductor segments. The condenser 18 is shunted by'auxiliaries which permit the condenser to discharge when potential'is removed therefrom, these auxiliaries in the preferred form of my invention being in the form of a relatively high inductance shunt and a relatlvely high resistance shunt 21.

The operation of the device shown in Fig. 1 is as follows:

As the interrupter disks which are rigidly connected with the spindle 22 rotate in the direction indicated by the arrow the brush 15 is placed in electrical engagement with one of the conductor segments 14 of the disk 7. A circuit is then produced from the battery 11 through conductor 10, brush 9, slip ring 8, spindle 22, conductor segment 14, brush 15, conductor 17 through'the load and back to the battery through the conductor 12. As the interrupter disk 7 continues to rotate the brush 15 leaves the conductor segment 14 and enters upon the insulator segment 13. At the time of the break, that is, at the time when the conductor segment 14 leaves the brush 15 and the insulator segment 13 is brought in engagement with the brush 15, the brush 16 due to its angular displacement relatively to the brush 15 has electrical engagement with the conductor segment 14, with the result that sparking is suppressed between the conductor segment 14 and the brush 15 at the time of break between these the brush 16 makes contact with the next conductor segment-14 Due to the fact that the condenser is substantially discharged at the time thebnish 16 makes contact with one of the conductor segments 14 no sparking will occur at such make. It is also apparent that no sparking can occur at the time of break between the brush 15 and the conductor segments 14, since the condenser is then in shunt across the gap.

In Fig. 2, 22 designates the interrupter comprising the slip ring 23, the interrupter disk 24, the disk 25 and the spindle 26 which nae eoo serves to connect the several disks together so that they may rotate in unison. The brush 27 has electrical engagement with the slip ring 23 and is connected with one side of the battery 28, the other side of thebatter being connected with one side of the loa The interrupter disk 24 contains the several insulator segments 29 and 29 and the several conductor segments shown at 30 and 30 The brush 32 rides on the periphery of the disk 24 and is arranged to have electrical engagement with the several conductor segments of the disk. The brush 32 is connected with the conductor 33 leading to one side of the load and connecting with one side of the condenser 34. The other side of the condenser is connected by the conductor 35 with the brush 36 resting against the periphery of the disk 25. The disk 25 contains the several conductor segments 37 and 37 and the several insulator segments 38 and 38 The inductance and resistance shunts 39 and 40 respectively are placed in shunt with the condenser 34 as illustrated.

The operation of the device just described is as follows As the interrupter disks are rotated in the direction indicated by the arrow the conductor segment 30 is moved to a position where it has electrical contact with the brush 32. This results in a circuit from the battery 28 through brush 27, slip ring 23,

spindle 26, conductor segment 30, brush 32,-

conductor 33, through the-loadand back to the battery 28. As the disk 24 is rotated and the conductor segment 30 leaves the brush 32 the disk 25 is moved to a position where the brush 36 has engaged the conductor segment 37, with the result that the condenser 34 is charged at the time of break between the conductor segment 30 and the brush 32. As the interrupter disks continue to rotate the insulator segment 38 is brought under the brush 36 to allow the condenser 34 to discharge through its shunts 39 and 40.

The arrangement shown in Fig. 2 gives the condenser 34 a greater interval of time within which to discharge than does the arrangement shown in Fig. 1. In Fig. 2 immediately after the condenser is charged it is disconnected from the battery 28 and continues to be disconnected from the battery until a very short time before the brush ments 51 and 51 The conductor segments are arranged to be engaged by the brush 52 connected with the conductor 53 leading to one side of the load and connecting with one side of the condenser 54. The other side of the condenser is connected with the conductor 55 leading to an armature 56 of the relay 57. When the armature 56 is attracted it engages the contact 58 connected with the conductor 47. One side of the relay coil is connected with the brush 52 as illus trated and the other side with the conductor 49 leading to one side of the battery.

The inductance and resistance shunts 59 and 60 respectively are placed in shunt with the condenser as in the previously described arrangements. The operation of the device illustrated in this figure is as follows:

When the interrupter disks are rotated in the direction indicated by the arrow the conductor segment 50 is brought into engagement with the brush 52 with the result that a circuit is provided through the load. In addition to this a circuit is provided from the brush 52 through the relay 57 and back to the battery which serves to attract the armature 56 and connect one side of the condenser with the battery. As the interrupter disks continue to rotate and a break occurs between the brush 52 and the conductor segment 50 the condenser 54 is charged, due to the fact that the relay lags a little behind the interruption. After the condenser is charged the relay becomes deenergized and the armature 56 is drawn away from its contact 58 so that the condenser may discharge through its shunts 59 and 60. The spark suppression means illustrated in this figure is such that it may be applied conveniently to any type of interrupter now on the market, the only thing necessary to attach the spark suppression means to the interrupter being that of providing the necessary electrical connections.

In Fig. 4 I have shown the arrangement of iny invention applied to the vibrating type of interrupter. In this figure, 61 designates the vibrator which comprises the coil 62, the armature 63 and the contact 64 which the armature is arranged to engage when it is in its unattracted position. The contact 64 connects with one side of the battery 65, the other side of the battery leading to one side of the load. The other side of the load is connected through the conductor 66 with one side of the coil 62. The other side of the coil is connected with the armature 63 and connects with one side of the condenser 67 through the conductor 68.

. ing the armature 70 to disconnect from the contact 71 to permit the condenser 67 to discharge through the inductance and resistance shunts 72 and 73 respectively. After the armature 70 has disconnected from the contact 71 the armature 63 engages the contact 64 so that the operation just described may be repeated.

In some instances it may be desirable to disconnect the condenser shunt auxiliaries when the condenser is being charged and to connect such auxiliaries in shunt with the condenser when discharge thereof occurs. In Fig. 5 I have illustrated such an arrangement applied to an interrupter of the type shown in Fig. 4. In this figure the arrangement is identical with that shown in Fig. 4 except that the armature 70 is arranged to engage the contact 71 when it is attracted by the coil 62 and to engage the contact 74 when it is in its unattracted position. The contact 74 connects with the inductance and resistance shunts 72 and 73 respectively while the armature 70 connects with one side of the condenser. It will be observed that upon attraction of the armature 70 the condenser is charged and that upon decnergization of the coil 62 the condenser is connected with the shunts 72 and 7 3 to permit its discharge. The coils 62 and 62 while shown connected in series with the load may be connected in parallel therewith.

It will be noted that in each of the embodiments of my invention described above, the condenser is not connected across the contacts until after the load circuit is closed. This feature of my invention is advantageous for the reason that it removes the load potential and gives the condenser a greater length of time in which to discharge and thereby insures that its voltage is substantially reduced to zero, and thereby insures that there will be no back discharge from the condenser which might injuriously affeet the contacts. So far as I am aware in all of the means heretofore employed for preventing sparking at interrupter contacts, the condenser is always connected across the contacts at the instant these contacts are closed. Such an arrangement is less eificient for the reason that it permits the back discharges from the condenser, which in time injuriously affect the contacts of the interrupter.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

1. The combination with a pair of interrupter contacts, of means for opening and closing said contacts, and means for preventing sparking between said contacts con-.

sisting of a shunt comprising a reactance, a resistance, and a condenser connected in parallel, and means for connecting said shunt across said contacts before said contacts are opened and after said contacts are closed.

2. The combination with a pair of interrupter contacts, of means for opening and closing said contacts, and means for preventing sparking between said contacts, consisting of a shunt comprising a condenser and a reactance connected in parallel, and means for connecting said condenser across said contacts before said contacts are opened and after said contacts are closed.

3. The combination with a pair of interrupter contacts, of means for opening and closing said contacts, and means for preventing sparking between said contacts, consistaesaaco rupter contacts, of means for opening and closing said contacts and means for preventlng sparking between sald contacts conslsting of a shunt across said contacts, said shuntcomprising a resistance and a reactance connected in parallel.

In witness whereof, I hereunto subscribe my name this 24: day of April, A. D. 1917.

WILLIAM J. CRUMP'LON.

l/Vitnesses H. W. Hnrnnnnnron, Gr. Sorirrm'r. 

